/* ===========================================
   Context Engineering — Design System v3
   =========================================== */

:root {
  --color-bg: #171614;
  --color-surface: #1c1b19;
  --color-surface-2: #201f1d;
  --color-surface-offset: #1d1c1a;
  --color-divider: #262523;
  --color-border: #393836;
  --color-text: #cdccca;
  --color-text-muted: #797876;
  --color-text-faint: #5a5957;
  --color-primary: #4f98a3;
  --color-primary-hover: #227f8b;
  --color-primary-highlight: #313b3b;
  --color-success: #6daa45;
  --color-warning: #c97a4a;
  --color-error: #c45a9a;

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.25);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.35);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.45);
  --shadow-glow: 0 0 20px rgba(79,152,163,0.12);

  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
  --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --text-lg: clamp(1.125rem, 1rem + 0.75vw, 1.5rem);
  --text-xl: clamp(1.5rem, 1.2rem + 1.25vw, 2.25rem);
  --text-2xl: clamp(2rem, 1.2rem + 2.5vw, 3.5rem);

  --font-display: 'Instrument Serif', Georgia, serif;
  --font-body: 'Satoshi', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;

  --easing: cubic-bezier(0.16, 1, 0.3, 1);
  --transition-fast: 120ms;
  --transition-base: 180ms;
  --transition-slow: 300ms;
}

[data-theme="light"] {
  --color-bg: #f7f6f2;
  --color-surface: #f9f8f5;
  --color-surface-2: #fbfbf9;
  --color-surface-offset: #f3f0ec;
  --color-divider: #dcd9d5;
  --color-border: #d4d1ca;
  --color-text: #28251d;
  --color-text-muted: #7a7974;
  --color-text-faint: #bab9b4;
  --color-primary: #01696f;
  --color-primary-hover: #0c4e54;
  --color-primary-highlight: #cedcd8;
  --color-success: #437a22;
  --color-warning: #964219;
  --color-error: #a12c7b;

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.12);
  --shadow-glow: 0 0 20px rgba(1,105,111,0.08);
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  color-scheme: dark;
}

html[data-theme="light"] {
  color-scheme: light;
}

::selection {
  background: var(--color-primary);
  color: white;
}

body {
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: 1.65;
  color: var(--color-text);
  background-color: var(--color-bg);
  transition: background-color var(--transition-base) var(--easing),
              color var(--transition-base) var(--easing);
}

img, video, svg {
  max-width: 100%;
  height: auto;
  display: block;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 400;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--color-text);
}

h1 { font-size: var(--text-2xl); }
h2 { font-size: var(--text-xl); }
h3 { font-size: var(--text-lg); }
h4 { font-size: var(--text-base); font-weight: 500; }

p {
  max-width: 72ch;
  color: var(--color-text-muted);
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition-fast) var(--easing);
}

a:hover {
  color: var(--color-primary-hover);
  text-decoration: underline;
}

a:focus-visible,
button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-4);
  padding: var(--space-2) var(--space-4);
  background: var(--color-primary);
  color: white;
  border-radius: var(--radius-sm);
  z-index: 9999;
  font-size: var(--text-sm);
  font-weight: 500;
  transition: top var(--transition-fast) var(--easing);
}

.skip-link:focus {
  top: var(--space-4);
}

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-6);
}

.prose {
  max-width: 72ch;
}

/* --- Header --- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(23, 22, 20, 0.85);
  border-bottom: 1px solid var(--color-divider);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  transition: background-color var(--transition-base) var(--easing);
}

[data-theme="light"] .site-header {
  background: rgba(247, 246, 242, 0.85);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-display);
  font-size: var(--text-lg);
  color: var(--color-text);
  text-decoration: none;
}

.logo:hover {
  text-decoration: none;
  color: var(--color-primary);
}

.logo svg {
  width: 28px;
  height: 28px;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

/* --- Theme Toggle --- */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all var(--transition-fast) var(--easing);
}

.theme-toggle:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-surface-2);
}

.theme-toggle svg {
  width: 20px;
  height: 20px;
  transition: opacity var(--transition-base) var(--easing),
              transform var(--transition-base) var(--easing);
}

.theme-toggle .icon-hidden {
  opacity: 0;
  transform: scale(0.8);
  position: absolute;
  pointer-events: none;
}

.theme-toggle .icon-visible {
  opacity: 1;
  transform: scale(1);
  position: relative;
}

/* --- Mobile Menu --- */
.mobile-menu-btn {
  display: none;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  color: var(--color-text);
  cursor: pointer;
}

.mobile-menu-btn svg {
  width: 24px;
  height: 24px;
}

.mobile-nav-drawer {
  position: fixed;
  top: 0;
  right: 0;
  width: 280px;
  height: 100vh;
  background: var(--color-surface);
  border-left: 1px solid var(--color-border);
  z-index: 200;
  padding: var(--space-8) var(--space-6);
  transform: translateX(100%);
  transition: transform var(--transition-slow) var(--easing);
  visibility: hidden;
}

.mobile-nav-drawer.open {
  transform: translateX(0);
  visibility: visible;
}

.mobile-nav-drawer ul {
  list-style: none;
  margin-top: var(--space-8);
}

.mobile-nav-drawer .nav-link {
  display: block;
  padding: var(--space-3) 0;
  font-size: var(--text-base);
  border-bottom: 1px solid var(--color-divider);
}

.overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 150;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-slow) var(--easing),
              visibility var(--transition-slow) var(--easing);
}

.overlay.visible {
  opacity: 1;
  visibility: visible;
}

/* --- Main Layout --- */
.main-layout {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: var(--space-8);
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-6);
}

/* --- Sidebar Nav --- */
.sidebar-nav {
  position: sticky;
  top: 80px;
  max-height: calc(100vh - 100px);
  overflow-y: auto;
  padding: var(--space-4) 0;
}

.sidebar-nav ul {
  list-style: none;
}

.sidebar-nav li {
  margin: 0;
}

.nav-link {
  display: block;
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  border-radius: var(--radius-sm);
  text-decoration: none;
  transition: all var(--transition-fast) var(--easing);
  border-left: 2px solid transparent;
}

.nav-link:hover {
  color: var(--color-text);
  background: var(--color-surface-offset);
  text-decoration: none;
}

.nav-link.active {
  color: var(--color-primary);
  background: var(--color-primary-highlight);
  border-left-color: var(--color-primary);
  font-weight: 500;
}

/* --- Sections --- */
section {
  padding: var(--space-24) 0;
  scroll-margin-top: 80px;
  content-visibility: auto;
  contain-intrinsic-size: 0 500px;
}

section:first-of-type {
  content-visibility: visible;
}

.section-eyebrow {
  font-size: var(--text-xs);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-primary);
  margin-bottom: var(--space-4);
}

.section-title {
  margin-bottom: var(--space-6);
}

.section-intro {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  margin-bottom: var(--space-12);
  max-width: 72ch;
}

/* --- Target Highlight --- */
:target {
  animation: targetPulse 1.5s var(--easing);
}

@keyframes targetPulse {
  0% { background: transparent; }
  20% { background: var(--color-primary-highlight); }
  100% { background: transparent; }
}

/* --- Hero --- */
.hero {
  padding: var(--space-24) 0 var(--space-20);
  text-align: center;
  position: relative;
  overflow: hidden;
  scroll-margin-top: 80px;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -50%;
  width: 200%;
  height: 200%;
  background: radial-gradient(ellipse at 50% 0%, var(--color-primary-highlight) 0%, transparent 60%);
  opacity: 0.4;
  pointer-events: none;
  z-index: 0;
}

.hero::after {
  content: '';
  position: absolute;
  inset: 0;
  background:
    linear-gradient(var(--color-primary-highlight) 1px, transparent 1px),
    linear-gradient(90deg, var(--color-primary-highlight) 1px, transparent 1px);
  background-size: 60px 60px;
  opacity: 0.04;
  pointer-events: none;
  z-index: 0;
  mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse at center, black 30%, transparent 70%);
}

[data-theme="light"] .hero::after {
  opacity: 0.06;
}

.hero .container {
  position: relative;
  z-index: 1;
}

.hero-headline {
  font-size: clamp(2.5rem, 2rem + 2.5vw, 4rem);
  line-height: 1.1;
  margin-bottom: var(--space-6);
  max-width: 900px;
  margin-left: auto;
  margin-right: auto;
}

.hero-subheadline {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  max-width: 680px;
  margin: 0 auto var(--space-8);
}

.hero-ctas {
  display: flex;
  gap: var(--space-4);
  justify-content: center;
  flex-wrap: wrap;
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 500;
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  cursor: pointer;
  text-decoration: none;
  transition: all var(--transition-fast) var(--easing);
  min-height: 44px;
  position: relative;
  overflow: hidden;
}

.btn-primary {
  background: var(--color-primary);
  color: white;
  border-color: var(--color-primary);
  box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
  background: var(--color-primary-hover);
  border-color: var(--color-primary-hover);
  color: white;
  text-decoration: none;
  box-shadow: var(--shadow-glow), var(--shadow-md);
  transform: translateY(-1px);
}

.btn-secondary {
  background: var(--color-surface);
  color: var(--color-text);
  border-color: var(--color-border);
}

.btn-secondary:hover {
  background: var(--color-surface-2);
  border-color: var(--color-primary);
  color: var(--color-primary);
  text-decoration: none;
  transform: translateY(-1px);
}


.btn-outline {
  background: transparent;
  color: var(--color-text-muted);
  border-color: var(--color-border);
}

.btn-outline:hover {
  background: var(--color-surface);
  border-color: var(--color-primary);
  color: var(--color-primary);
  text-decoration: none;
  transform: translateY(-1px);
}

.book-download-callout-action {
  margin-top: var(--space-4);
  margin-bottom: 0;
}

.hero-downloads {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  justify-content: center;
  align-items: center;
  margin-top: var(--space-6);
}

.hero-downloads-label {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

.download-format-group {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  align-items: center;
}

.btn-sm {
  padding: var(--space-2) var(--space-4);
  font-size: var(--text-xs);
  min-height: 36px;
}

/* --- Cards --- */
.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  transition: transform var(--transition-base) var(--easing),
              box-shadow var(--transition-base) var(--easing),
              border-color var(--transition-base) var(--easing);
  text-align: left;
  position: relative;
  overflow: hidden;
}

.card.card-interactive {
  transition: transform var(--transition-base) var(--easing),
              box-shadow var(--transition-base) var(--easing),
              border-color var(--transition-base) var(--easing);
}

.card::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--color-primary);
  opacity: 0;
  transition: opacity var(--transition-base) var(--easing);
}

.card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-primary);
}

.card:hover::before {
  opacity: 1;
}

.card-title {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  margin-bottom: var(--space-2);
  color: var(--color-text);
}

.card-meta {
  font-size: var(--text-xs);
  color: var(--color-primary);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-3);
}

.card-body {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
}

.card-body p {
  margin-bottom: var(--space-3);
}

/* --- Accordion --- */
.accordion-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-3);
  background: var(--color-surface);
  overflow: hidden;
}

.accordion-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: var(--space-4) var(--space-6);
  background: none;
  border: none;
  cursor: pointer;
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: 500;
  color: var(--color-text);
  text-align: left;
  transition: background var(--transition-fast) var(--easing);
}

.accordion-header:hover {
  background: var(--color-surface-offset);
}

.accordion-header .accordion-icon {
  width: 20px;
  height: 20px;
  color: var(--color-text-muted);
  transition: transform var(--transition-base) var(--easing);
  flex-shrink: 0;
}

.accordion-item.open .accordion-icon {
  transform: rotate(180deg);
}

.accordion-content {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows var(--transition-slow) var(--easing);
}

.accordion-item.open .accordion-content {
  grid-template-rows: 1fr;
}

.accordion-body {
  padding: 0 var(--space-6) var(--space-6);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.7;
  overflow: hidden;
}

/* --- Tables --- */
.table-wrapper {
  overflow-x: auto;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  margin: var(--space-8) 0;
  -webkit-overflow-scrolling: touch;
}

table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--text-sm);
}

th {
  background: var(--color-surface-offset);
  padding: var(--space-3) var(--space-4);
  text-align: left;
  font-weight: 600;
  color: var(--color-text);
  border-bottom: 1px solid var(--color-border);
  white-space: nowrap;
}

td {
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--color-divider);
  color: var(--color-text-muted);
  vertical-align: top;
  transition: background var(--transition-fast) var(--easing);
}

tr:last-child td {
  border-bottom: none;
}

tr:hover td {
  background: rgba(79, 152, 163, 0.06);
}

[data-theme="light"] tr:hover td {
  background: rgba(1, 105, 111, 0.06);
}

/* --- Code Blocks --- */
.code-block {
  position: relative;
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  margin: var(--space-6) 0;
  overflow: hidden;
}

.code-block pre {
  padding: var(--space-6);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-text);
  tab-size: 2;
  -webkit-overflow-scrolling: touch;
}

.code-block .copy-btn {
  position: absolute;
  top: var(--space-3);
  right: var(--space-3);
  padding: var(--space-2) var(--space-3);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-family: var(--font-body);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all var(--transition-fast) var(--easing);
}

.code-block .copy-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-surface-2);
}

.code-block .copy-btn.copied {
  color: var(--color-success);
  border-color: var(--color-success);
  background: rgba(109, 170, 69, 0.1);
}

/* Inline code */
code {
  font-family: var(--font-mono);
  font-size: 0.9em;
  background: var(--color-surface-2);
  padding: 0.15em 0.4em;
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border);
  color: var(--color-text);
}

pre code {
  background: transparent;
  padding: 0;
  border: none;
  font-size: inherit;
}

/* --- Forms --- */
.form-group {
  margin-bottom: var(--space-6);
}

.form-label {
  display: block;
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.form-input,
.form-textarea,
.form-select {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  color: var(--color-text);
  transition: border-color var(--transition-fast) var(--easing),
              box-shadow var(--transition-fast) var(--easing);
}

.form-input:focus,
.form-textarea:focus,
.form-select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(79, 152, 163, 0.2);
}

[data-theme="light"] .form-input:focus,
[data-theme="light"] .form-textarea:focus,
[data-theme="light"] .form-select:focus {
  box-shadow: 0 0 0 3px rgba(1, 105, 111, 0.15);
}

.form-textarea {
  min-height: 120px;
  resize: vertical;
}

.form-select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23797876' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right var(--space-4) center;
  padding-right: var(--space-8);
}

[data-theme="light"] .form-select {
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%237a7974' d='M6 8L1 3h10z'/%3E%3C/svg%3E");
}

.form-hint {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  margin-top: var(--space-1);
}

/* --- Slider --- */
.slider-container {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

input[type="range"] {
  flex: 1;
  height: 6px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--color-divider);
  border-radius: 3px;
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  background: var(--color-primary);
  border-radius: 50%;
  cursor: pointer;
  border: 2px solid var(--color-bg);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-fast) var(--easing),
              box-shadow var(--transition-fast) var(--easing);
}

input[type="range"]::-webkit-slider-thumb:hover {
  transform: scale(1.15);
  box-shadow: var(--shadow-glow);
}

input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  background: var(--color-primary);
  border-radius: 50%;
  cursor: pointer;
  border: 2px solid var(--color-bg);
  box-shadow: var(--shadow-sm);
}

.slider-value {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-primary);
  min-width: 48px;
  text-align: right;
}

/* --- Numbered List --- */
.numbered-list {
  list-style: none;
  counter-reset: item;
}

.numbered-list li {
  position: relative;
  padding-left: var(--space-8);
  margin-bottom: var(--space-4);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.7;
}

.numbered-list li::before {
  counter-increment: item;
  content: counter(item);
  position: absolute;
  left: 0;
  top: 0;
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary-highlight);
  color: var(--color-primary);
  border-radius: 50%;
  font-size: var(--text-xs);
  font-weight: 600;
}

/* --- Checklist --- */
.checklist {
  list-style: none;
}

.checklist li {
  position: relative;
  padding-left: var(--space-8);
  margin-bottom: var(--space-3);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
}

.checklist li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 2px;
  width: 18px;
  height: 18px;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
}

/* --- Grid Layouts --- */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-6);
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-6);
}

/* --- Utility --- */
.text-center { text-align: center; }
.text-left { text-align: left; }
.mt-4 { margin-top: var(--space-4); }
.mt-8 { margin-top: var(--space-8); }
.mt-12 { margin-top: var(--space-12); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-8 { margin-bottom: var(--space-8); }
.mb-12 { margin-bottom: var(--space-12); }

/* --- Reading Progress Bar --- */
.reading-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-success));
  z-index: 9999;
  width: 0%;
  transition: width 100ms linear;
  will-change: width;
}

/* --- Section Dividers --- */
.section-divider {
  height: 1px;
  background: linear-gradient(90deg, transparent 0%, var(--color-primary) 20%, var(--color-primary) 80%, transparent 100%);
  opacity: 0.15;
  margin: 0 auto;
  max-width: 600px;
}

/* --- Hero Particles Canvas --- */
.hero-particles {
  position: absolute;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.hero-particles canvas {
  width: 100%;
  height: 100%;
}

/* --- Layer Stack Diagram --- */
.layer-stack {
  display: flex;
  flex-direction: column;
  gap: 0;
  perspective: 1000px;
  margin: var(--space-8) 0;
  max-width: 480px;
}

.layer-stack-item {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-3) var(--space-4);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-base) var(--easing);
  transform: rotateX(2deg);
  transform-origin: top center;
  position: relative;
}

.layer-stack-item:not(:first-child) {
  margin-top: -1px;
  border-top-left-radius: 0;
  border-top-right-radius: 0;
}

.layer-stack-item:not(:last-child) {
  border-bottom-left-radius: 0;
  border-bottom-right-radius: 0;
}

.layer-stack-item:hover {
  background: var(--color-surface-2);
  border-color: var(--color-primary);
  z-index: 2;
  transform: rotateX(0deg) translateX(6px);
  box-shadow: var(--shadow-md), 4px 0 0 0 var(--color-primary);
}

.layer-stack-item.active {
  background: var(--color-primary-highlight);
  border-color: var(--color-primary);
  z-index: 3;
  transform: rotateX(0deg) translateX(8px);
  box-shadow: var(--shadow-md), 4px 0 0 0 var(--color-primary);
}

.layer-stack-num {
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary);
  color: white;
  border-radius: 50%;
  font-size: var(--text-xs);
  font-weight: 600;
  flex-shrink: 0;
}

.layer-stack-label {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text);
}

.layer-stack-tag {
  margin-left: auto;
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  background: var(--color-surface-offset);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
}

/* --- Interactive Card Depth --- */
.card-interactive {
  position: relative;
  transition: transform var(--transition-base) var(--easing),
              box-shadow var(--transition-base) var(--easing),
              border-color var(--transition-base) var(--easing);
}

.card-interactive::after {
  content: '';
  position: absolute;
  inset: 0;
  border-radius: var(--radius-lg);
  background: radial-gradient(600px circle at var(--mouse-x, 50%) var(--mouse-y, 50%), rgba(79,152,163,0.06), transparent 40%);
  pointer-events: none;
  opacity: 0;
  transition: opacity var(--transition-base) var(--easing);
}

.card-interactive:hover::after {
  opacity: 1;
}

[data-theme="light"] .card-interactive::after {
  background: radial-gradient(600px circle at var(--mouse-x, 50%) var(--mouse-y, 50%), rgba(1,105,111,0.04), transparent 40%);
}

/* --- Sidebar Progress --- */
.sidebar-progress {
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--color-divider);
}

.sidebar-progress-fill {
  width: 100%;
  background: var(--color-primary);
  height: 0%;
  transition: height 100ms linear;
}

/* --- Tooltip --- */
[data-tooltip] {
  position: relative;
}

[data-tooltip]::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: calc(100% + 8px);
  left: 50%;
  transform: translateX(-50%) translateY(4px);
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  color: var(--color-text);
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
  font-family: var(--font-body);
  white-space: nowrap;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-fast) var(--easing),
              transform var(--transition-fast) var(--easing),
              visibility var(--transition-fast) var(--easing);
  z-index: 10;
  pointer-events: none;
}

[data-tooltip]:hover::after {
  opacity: 1;
  visibility: visible;
  transform: translateX(-50%) translateY(0);
}

/* --- Jargon Explainer System --- */
.jargon-term {
  border-bottom: 1.5px dotted var(--color-primary);
  cursor: help;
  transition: background var(--transition-fast) var(--easing),
              color var(--transition-fast) var(--easing);
}

.jargon-term:hover,
.jargon-term.focus {
  background: var(--color-primary-highlight);
  border-bottom-style: solid;
}

.jargon-panel {
  position: fixed;
  z-index: 300;
  width: 340px;
  max-width: calc(100vw - 32px);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  padding: var(--space-6);
  opacity: 0;
  visibility: hidden;
  transform: translateY(6px);
  transition: opacity var(--transition-fast) var(--easing),
              transform var(--transition-fast) var(--easing),
              visibility var(--transition-fast) var(--easing);
  pointer-events: auto;
  font-size: var(--text-sm);
  line-height: 1.55;
}

.jargon-panel.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.jargon-panel-term {
  font-family: var(--font-display);
  font-size: var(--text-base);
  font-weight: 500;
  color: var(--color-primary);
  margin-bottom: var(--space-3);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.jargon-panel-close {
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-surface-2);
  color: var(--color-text-muted);
  cursor: pointer;
  font-size: var(--text-xs);
  transition: all var(--transition-fast) var(--easing);
  flex-shrink: 0;
}

.jargon-panel-close:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-surface-offset);
}

.jargon-panel-body {
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
}

.jargon-panel-see-also {
  border-top: 1px solid var(--color-divider);
  padding-top: var(--space-3);
}

.jargon-panel-see-also-label {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-2);
}

.jargon-panel-see-also a {
  display: inline-block;
  margin: 0 var(--space-2) var(--space-1) 0;
  font-size: var(--text-xs);
  color: var(--color-primary);
  border-bottom: 1px dotted var(--color-primary);
  cursor: pointer;
  text-decoration: none;
  transition: color var(--transition-fast) var(--easing);
}

.jargon-panel-see-also a:hover {
  color: var(--color-primary-hover);
  border-bottom-style: solid;
}

/* --- Jargon Toggle Button --- */
.jargon-toggle {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-3);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  color: var(--color-text-muted);
  cursor: pointer;
  font-family: var(--font-body);
  font-size: var(--text-xs);
  font-weight: 500;
  transition: all var(--transition-fast) var(--easing);
  white-space: nowrap;
}

.jargon-toggle:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-surface-2);
}

.jargon-toggle.active {
  background: var(--color-primary-highlight);
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.jargon-toggle svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

@media (max-width: 768px) {
  .jargon-panel {
    width: calc(100vw - 32px);
    left: 16px !important;
    right: 16px;
  }
}

/* --- Scroll Animations --- */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--transition-slow) var(--easing),
              transform var(--transition-slow) var(--easing);
  will-change: opacity, transform;
}

.no-js .reveal,
.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

.stagger > * {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--transition-slow) var(--easing),
              transform var(--transition-slow) var(--easing);
  will-change: opacity, transform;
}

.no-js .stagger > *,
.stagger.visible > *:nth-child(1) { transition-delay: 0ms; opacity: 1; transform: translateY(0); }
.stagger.visible > *:nth-child(2) { transition-delay: 50ms; opacity: 1; transform: translateY(0); }
.stagger.visible > *:nth-child(3) { transition-delay: 100ms; opacity: 1; transform: translateY(0); }
.stagger.visible > *:nth-child(4) { transition-delay: 150ms; opacity: 1; transform: translateY(0); }
.stagger.visible > *:nth-child(5) { transition-delay: 200ms; opacity: 1; transform: translateY(0); }
.stagger.visible > *:nth-child(6) { transition-delay: 250ms; opacity: 1; transform: translateY(0); }
.stagger.visible > *:nth-child(7) { transition-delay: 300ms; opacity: 1; transform: translateY(0); }
.stagger.visible > *:nth-child(8) { transition-delay: 350ms; opacity: 1; transform: translateY(0); }

/* --- SVG Diagram --- */
.ace-diagram {
  width: 100%;
  max-width: 800px;
  margin: var(--space-8) auto;
}

.ace-diagram svg {
  width: 100%;
  height: auto;
}

.ace-diagram .diagram-path {
  stroke-dasharray: 1000;
  stroke-dashoffset: 1000;
  transition: stroke-dashoffset 1.5s var(--easing);
}

.ace-diagram.visible .diagram-path {
  stroke-dashoffset: 0;
}

/* --- Stat Counter --- */
.stat-value {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  color: var(--color-primary);
  line-height: 1;
}

.stat-value[data-count] {
  display: inline-block;
}

.counter-display {
  display: inline;
}

.no-js .counter-display {
  display: none;
}

.stat-label {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-top: var(--space-2);
}

/* --- Hero Typing Cursor --- */
.hero-headline .typing-cursor {
  display: inline-block;
  width: 3px;
  height: 1em;
  background: var(--color-primary);
  margin-left: 2px;
  animation: blink 1s steps(1) infinite;
  vertical-align: baseline;
}

@keyframes blink {
  0%, 50% { opacity: 1; }
  51%, 100% { opacity: 0; }
}

/* --- Callout Box --- */
.callout-box {
  background: var(--color-primary-highlight);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  position: relative;
  overflow: hidden;
}

.callout-box::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--color-primary);
  opacity: 0.6;
}

/* --- Blueprint Form --- */
.blueprint-layer {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  margin-bottom: var(--space-6);
  position: relative;
  overflow: hidden;
}

.blueprint-layer::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--color-primary);
  opacity: 0.3;
}

.blueprint-layer-header {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-6);
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--color-divider);
}

.layer-number {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary);
  color: white;
  border-radius: 50%;
  font-size: var(--text-sm);
  font-weight: 600;
  flex-shrink: 0;
  box-shadow: var(--shadow-sm);
}

.layer-title {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  color: var(--color-text);
}

/* --- Output Area --- */
.output-area {
  background: var(--color-surface-2);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  margin-top: var(--space-8);
  animation: fadeSlideUp var(--transition-slow) var(--easing);
}

@keyframes fadeSlideUp {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.output-area h3 {
  margin-bottom: var(--space-4);
}

/* --- Back to Top --- */
.back-to-top {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  color: var(--color-text-muted);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: all var(--transition-base) var(--easing);
  z-index: 90;
  box-shadow: var(--shadow-md);
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-surface-2);
}

.back-to-top svg {
  width: 20px;
  height: 20px;
}

/* --- Footer --- */
.site-footer {
  border-top: 1px solid var(--color-divider);
  padding: var(--space-12) 0;
  margin-top: var(--space-16);
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--text-sm);
  color: var(--color-text-faint);
}

/* --- Responsive --- */
@media (max-width: 1024px) {
  .main-layout {
    grid-template-columns: 1fr;
  }

  .sidebar-nav {
    display: none;
  }

  .mobile-menu-btn {
    display: flex;
  }

  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }

  .layer-stack-grid {
    grid-template-columns: 1fr !important;
  }
}

@media (max-width: 768px) {
  .grid-2,
  .grid-4 {
    grid-template-columns: 1fr;
  }

  .hero-headline {
    font-size: clamp(1.75rem, 1.5rem + 1.5vw, 2.5rem);
  }

  .hero-ctas {
    flex-direction: column;
    align-items: center;
  }

  .btn {
    width: 100%;
    max-width: 280px;
  }

  section {
    padding: var(--space-16) 0;
  }

  .container,
  .main-layout {
    padding: 0 var(--space-4);
  }

  .footer-content {
    flex-direction: column;
    gap: var(--space-2);
    text-align: center;
  }

  .back-to-top {
    right: var(--space-4);
    bottom: var(--space-4);
  }

  .layer-stack {
    max-width: 100%;
  }

  .hero-particles {
    display: none;
  }
}

/* --- Print Styles --- */
@media print {
  .site-header,
  .sidebar-nav,
  .mobile-menu-btn,
  .theme-toggle,
  .back-to-top,
  .overlay,
  .mobile-nav-drawer {
    display: none !important;
  }

  .main-layout {
    grid-template-columns: 1fr;
    padding: 0;
    max-width: none;
  }

  section {
    content-visibility: visible;
    padding: 1rem 0;
    page-break-inside: avoid;
  }

  .card {
    break-inside: avoid;
    box-shadow: none;
    border: 1px solid #ccc;
  }

  body {
    background: white;
    color: black;
  }

  a {
    color: #000;
    text-decoration: underline;
  }

  a[href]::after {
    content: ' (' attr(href) ')';
    font-size: 0.8em;
    opacity: 0.7;
  }

  .code-block {
    background: #f5f5f5;
    border: 1px solid #ddd;
  }

  .btn {
    background: #eee;
    border: 1px solid #999;
    color: #333;
  }
}

/* --- Reduced Motion --- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .reveal,
  .stagger > * {
    opacity: 1;
    transform: none;
  }

  .ace-diagram .diagram-path {
    stroke-dashoffset: 0;
  }

  .output-area {
    animation: none;
  }

  .reading-progress,
  .hero-particles,
  .hero::after {
    display: none;
  }

  .layer-stack-item {
    transform: none;
  }

  .hero-headline .typing-cursor {
    animation: none;
    opacity: 0;
  }
}

/* --- Playbook v4: Budget, Ladder, Tools --- */
.nav-group-label {
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-faint);
  padding: var(--space-4) var(--space-3) var(--space-2);
  margin-top: var(--space-2);
}

.nav-group-label:first-child {
  margin-top: 0;
}

.ladder-steps {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  margin: var(--space-8) 0;
}

.ladder-step {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--space-4);
  align-items: start;
  padding: var(--space-4) var(--space-6);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  border-left: 4px solid var(--color-primary);
}

.ladder-step-num {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  color: var(--color-primary);
  line-height: 1;
}

.budget-bars {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  margin: var(--space-8) 0;
}

.budget-bar-row {
  display: grid;
  grid-template-columns: 140px 1fr 60px;
  gap: var(--space-4);
  align-items: center;
}

.budget-bar-label {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

.budget-bar-track {
  height: 12px;
  background: var(--color-surface-offset);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.budget-bar-fill {
  height: 100%;
  border-radius: var(--radius-sm);
  background: var(--color-primary);
  transition: width 0.6s var(--easing);
}

.budget-bar-fill.over-limit {
  background: var(--color-error);
}

.budget-bar-pct {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-text);
  text-align: right;
}

.injection-order {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin: var(--space-8) 0;
  padding: var(--space-6);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.injection-step {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
}

.injection-step.primacy { background: rgba(79, 152, 163, 0.15); border-left: 3px solid var(--color-primary); }
.injection-step.middle { background: var(--color-surface-offset); opacity: 0.85; }
.injection-step.recency { background: rgba(109, 170, 69, 0.12); border-left: 3px solid var(--color-success); }

.injection-zone-tag {
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text-faint);
  min-width: 72px;
}

.callout-warning {
  background: rgba(201, 122, 74, 0.1);
  border: 1px solid var(--color-warning);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  margin: var(--space-8) 0;
}

.callout-warning strong {
  color: var(--color-warning);
}

.toggle-group {
  display: inline-flex;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  margin-bottom: var(--space-6);
}

.toggle-btn {
  padding: var(--space-2) var(--space-4);
  background: var(--color-surface);
  border: none;
  color: var(--color-text-muted);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  cursor: pointer;
  transition: all var(--transition-fast) var(--easing);
}

.toggle-btn:hover {
  background: var(--color-surface-2);
  color: var(--color-text);
}

.toggle-btn.active {
  background: var(--color-primary);
  color: white;
}

.prompt-compare {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  margin: var(--space-6) 0;
}

.prompt-compare.hidden {
  display: none;
}

.ten-point-list {
  counter-reset: point;
  list-style: none;
  display: grid;
  gap: var(--space-4);
  margin: var(--space-8) 0;
}

.ten-point-list li {
  counter-increment: point;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--space-4);
  padding: var(--space-4);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  max-width: none;
  color: var(--color-text-muted);
}

.ten-point-list li::before {
  content: counter(point);
  width: 28px;
  height: 28px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary);
  color: white;
  border-radius: 50%;
  font-size: var(--text-sm);
  font-weight: 600;
  flex-shrink: 0;
}

.workflow-ladder {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-4);
  margin: var(--space-8) 0;
}

.workflow-rung {
  text-align: center;
  padding: var(--space-6);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  position: relative;
}

.workflow-rung.highlight {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-glow);
}

.workflow-rung::after {
  content: '→';
  position: absolute;
  right: -18px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-faint);
  font-size: var(--text-lg);
}

.workflow-rung:last-child::after {
  display: none;
}

.keybinding-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--space-4);
  margin: var(--space-8) 0;
}

.kbd-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.kbd-item kbd {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  padding: var(--space-1) var(--space-2);
  background: var(--color-surface-offset);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  white-space: nowrap;
}

.tool-section {
  background: var(--color-surface-offset);
  border-top: 1px solid var(--color-divider);
}

.tool-section .section-eyebrow {
  color: var(--color-primary);
}

.audit-report {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  white-space: pre-wrap;
  line-height: 1.6;
}

.audit-flag {
  color: var(--color-error);
  font-weight: 600;
}

.audit-ok {
  color: var(--color-success);
}

.wizard-result {
  padding: var(--space-6);
  border-radius: var(--radius-lg);
  border: 2px solid var(--color-primary);
  background: var(--color-primary-highlight);
  margin-top: var(--space-6);
}

.wizard-result h4 {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  margin-bottom: var(--space-3);
}

.source-footnote {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  margin-top: var(--space-6);
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-divider);
}

.source-footnote a {
  color: var(--color-text-muted);
}

.subsection-title {
  margin-top: var(--space-12);
  margin-bottom: var(--space-6);
}

.matrix-highlight {
  background: var(--color-primary-highlight);
}

.evolution-ladder {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-4);
  margin: var(--space-8) 0;
}

.evolution-rung {
  text-align: center;
  padding: var(--space-6);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  position: relative;
}

.evolution-rung.active-rung {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-glow);
}

.evolution-rung::after {
  content: '→';
  position: absolute;
  right: -14px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-faint);
}

.evolution-rung:last-child::after {
  display: none;
}

.three-component-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
  margin: var(--space-8) 0;
}

.component-card {
  padding: var(--space-6);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  border-top: 3px solid var(--color-primary);
}

.factor-checklist {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--space-6);
  margin: var(--space-8) 0;
}

.factor-card {
  padding: var(--space-6);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.factor-card h4 {
  color: var(--color-primary);
  margin-bottom: var(--space-3);
}

.wizard-reasons {
  margin-top: var(--space-4);
  padding-left: var(--space-6);
  color: var(--color-text-muted);
}

.wizard-reasons li {
  margin-bottom: var(--space-2);
  max-width: none;
}

.wizard-agent { border-color: var(--color-success); }
.wizard-workflow { border-color: var(--color-warning); }
.wizard-hybrid { border-color: var(--color-primary); }

.claude-md-tree {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  padding: var(--space-6);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  margin: var(--space-8) 0;
  line-height: 1.8;
}

.routine-example {
  padding: var(--space-6);
  background: var(--color-surface);
  border-left: 4px solid var(--color-primary);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-6);
}

.routine-example h4 {
  margin-bottom: var(--space-3);
}

/* --- Curriculum Grid --- */
.curriculum-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--space-6);
  margin: var(--space-8) 0;
}

.curriculum-module {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  position: relative;
  transition: transform var(--transition-base) var(--easing),
              box-shadow var(--transition-base) var(--easing),
              border-color var(--transition-base) var(--easing);
  overflow: hidden;
}

.curriculum-module::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--color-primary);
  opacity: 0.5;
  transition: opacity var(--transition-base) var(--easing);
}

.curriculum-module:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-primary);
}

.curriculum-module:hover::before {
  opacity: 1;
}

.curriculum-module.featured {
  border-color: var(--color-primary);
  background: var(--color-primary-highlight);
  box-shadow: var(--shadow-glow);
}

.curriculum-module.featured::before {
  background: var(--color-primary);
  opacity: 1;
}

.curriculum-module-header {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.curriculum-module-num {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  color: var(--color-primary);
  line-height: 1;
  flex-shrink: 0;
  min-width: 36px;
}

.curriculum-module-title {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  color: var(--color-text);
  margin: 0;
  line-height: 1.3;
}

.curriculum-module-meta {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  margin-top: var(--space-1);
}

.curriculum-module-desc {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
  margin-bottom: var(--space-4);
}

.curriculum-module-topics {
  list-style: none;
  padding: 0;
  margin: 0;
  border-top: 1px solid var(--color-divider);
  padding-top: var(--space-4);
}

.curriculum-module-topics li {
  position: relative;
  padding-left: var(--space-4);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  margin-bottom: var(--space-2);
  line-height: 1.5;
}

.curriculum-module-topics li::before {
  content: '▸';
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-size: 0.8em;
}

/* --- Strategy Cards (Four Core Strategies) --- */
.strategy-card {
  position: relative;
  overflow: hidden;
}

.strategy-card .card-meta {
  color: var(--color-primary);
  font-weight: 600;
  letter-spacing: 0.08em;
}

.strategy-card[data-strategy="write"]::before { background: #4f98a3; }
.strategy-card[data-strategy="select"]::before { background: #6daa45; }
.strategy-card[data-strategy="compress"]::before { background: #c97a4a; }
.strategy-card[data-strategy="isolate"]::before { background: #c45a9a; }

/* --- MCP Stats --- */
.mcp-stats {
  margin: var(--space-8) 0;
}

/* --- Instructor Grid --- */
.instructor-grid {
  margin-top: var(--space-8);
}

@media (max-width: 768px) {
  .evolution-ladder,
  .three-component-grid {
    grid-template-columns: 1fr;
  }

  .evolution-rung::after {
    content: '↓';
    right: auto;
    left: 50%;
    top: auto;
    bottom: -18px;
    transform: translateX(-50%);
  }
}

@media (max-width: 768px) {
  .workflow-ladder {
    grid-template-columns: 1fr;
  }

  .workflow-rung::after {
    content: '↓';
    right: auto;
    left: 50%;
    top: auto;
    bottom: -20px;
    transform: translateX(-50%);
  }

  .budget-bar-row {
    grid-template-columns: 1fr;
    gap: var(--space-2);
  }

  .budget-bar-pct {
    text-align: left;
  }
}

/* --- Color Scheme Auto --- */
@media (prefers-color-scheme: dark) {
  html:not([data-theme]) {
    --color-bg: #171614;
    --color-surface: #1c1b19;
    --color-surface-2: #201f1d;
    --color-surface-offset: #1d1c1a;
    --color-divider: #262523;
    --color-border: #393836;
    --color-text: #cdccca;
    --color-text-muted: #797876;
    --color-text-faint: #5a5957;
    --color-primary: #4f98a3;
    --color-primary-hover: #227f8b;
    --color-primary-highlight: #313b3b;
    --color-success: #6daa45;
    --color-warning: #c97a4a;
    --color-error: #c45a9a;
    color-scheme: dark;
  }
}

/* ===========================================
   AI Spec Genesis
   =========================================== */

.sg-step {
  margin-top: var(--space-8);
}

.sg-step-header {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  margin-bottom: var(--space-3);
}

.sg-step-num {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  border-radius: 50%;
  background: var(--color-primary);
  color: #fff;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: 700;
  flex-shrink: 0;
}

.sg-step-title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  margin: 0;
}

.sg-step-desc {
  color: var(--color-text-muted);
  max-width: 72ch;
  margin-bottom: var(--space-6);
}

.sg-step-hint {
  color: var(--color-text-muted);
  font-size: var(--text-sm);
  margin-bottom: var(--space-6);
  max-width: 72ch;
}

.sg-provider-row {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: var(--space-4);
  margin-bottom: var(--space-4);
}

@media (max-width: 768px) {
  .sg-provider-row {
    grid-template-columns: 1fr;
  }
}

.sg-provider-actions {
  margin-top: var(--space-2);
  margin-bottom: var(--space-2);
}

.sg-key-link {
  display: inline-block;
  font-size: var(--text-xs);
  color: var(--color-primary);
  text-decoration: none;
  margin-top: var(--space-1);
}

.sg-key-link:hover {
  text-decoration: underline;
}

.sg-privacy-note {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  margin-top: var(--space-2);
}

.sg-status {
  font-size: var(--text-sm);
  margin-top: var(--space-2);
  min-height: 1.25rem;
}

.sg-status.ok { color: var(--color-success); }
.sg-status.err { color: var(--color-error); }

.sg-examples {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  align-items: center;
  margin-bottom: var(--space-6);
}

.sg-examples-label {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

.sg-example-chip {
  font-family: var(--font-body);
  font-size: var(--text-xs);
  padding: 0.35rem 0.75rem;
  border: 1px solid var(--color-border);
  border-radius: 999px;
  background: transparent;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: all var(--transition-base) var(--easing);
}

.sg-example-chip:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--color-primary-highlight);
}

.sg-loading {
  display: inline-block;
  margin-left: var(--space-4);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

.sg-loading::after {
  content: '';
  display: inline-block;
  width: 1ch;
  animation: sg-blink 1s steps(3) infinite;
}

@keyframes sg-blink {
  0% { content: '.'; }
  33% { content: '..'; }
  66% { content: '...'; }
}

/* Decision points */
.sg-decision {
  margin-bottom: var(--space-8);
  padding: var(--space-6);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
}

.sg-decision-q {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  margin-bottom: var(--space-1);
}

.sg-decision-helper {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-6);
}

.sg-options {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--space-4);
}

.sg-option {
  position: relative;
  padding: var(--space-4);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-md);
  background: var(--color-surface-2);
  cursor: pointer;
  transition: border-color var(--transition-base) var(--easing), background var(--transition-base) var(--easing);
}

.sg-option:hover {
  border-color: var(--color-primary);
}

.sg-option.selected {
  border-color: var(--color-primary);
  background: var(--color-primary-highlight);
  box-shadow: var(--shadow-glow);
}

.sg-option-recommend-badge {
  position: absolute;
  top: -10px;
  right: var(--space-3);
  font-size: var(--text-xs);
  font-weight: 700;
  padding: 0.15rem 0.5rem;
  border-radius: 999px;
  background: var(--color-primary);
  color: #fff;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.sg-option-title {
  font-weight: 600;
  margin-bottom: var(--space-2);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.sg-option-desc {
  font-size: var(--text-sm);
  color: var(--color-text);
  margin-bottom: var(--space-3);
}

.sg-option-meta {
  font-size: var(--text-xs);
  margin-top: var(--space-2);
}

.sg-option-meta-label {
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-size: 0.65rem;
  color: var(--color-text-faint);
  display: block;
  margin-top: var(--space-2);
}

.sg-option-pros { color: var(--color-success); }
.sg-option-cons { color: var(--color-warning); }

.sg-option-rec-reason {
  font-size: var(--text-xs);
  color: var(--color-primary);
  font-style: italic;
  margin-top: var(--space-3);
  padding-top: var(--space-2);
  border-top: 1px dashed var(--color-border);
}

/* Output tabs */
.sg-output-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
}

.sg-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
  border-bottom: 1px solid var(--color-border);
  margin-bottom: var(--space-6);
}

.sg-tab {
  font-family: var(--font-body);
  font-size: var(--text-sm);
  padding: 0.5rem 0.9rem;
  border: none;
  border-bottom: 2px solid transparent;
  background: transparent;
  color: var(--color-text-muted);
  cursor: pointer;
  transition: color var(--transition-base) var(--easing), border-color var(--transition-base) var(--easing);
  margin-bottom: -1px;
}

.sg-tab:hover { color: var(--color-text); }

.sg-tab.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
  font-weight: 600;
}

.sg-tab-panel {
  display: none;
}

.sg-tab-panel.active {
  display: block;
}

.sg-tab-panel .code-block {
  margin: 0;
}

.sg-tab-panel .code-block pre {
  max-height: 60vh;
  overflow: auto;
}